Bacterial infection with Staphylococcus aureus is responsible for a large portion of soft tissue and skin infections seen in physician's offices and hospitals. Compounding this problem, many strains of S. aureus are becoming resistant to current antibiotic therapies, both topical and systemic.
Currently topical treatment have used of agents including cleansers such as chlorhexidine, a bactericidal agent, as well as silver and iodine. Topical antibiotics such as mupirocin, have been used, although resistant organisms have evolved. Other older topical antibiotics, such as neomycin, bacitracin, and polymyxin have several drawbacks, such as an incidence of allergic reactions and ineffective treatment of S. aureus. 
Topical nitric oxide donors, such as the S-nitrosothiols, have also been used to treat such bacterial infections, but the use of such topical nitric oxide donors has been limited for various reasons such as lack of stability. In some cases, sialin hydrogels have been used to facilitate nitric oxide delivery. Typically, in these systems, a nitrate, used as a precursor of nitric oxide, is placed in a nanoparticle, and the nitrite must then be reduced in vivo to nitric oxide by the action of water mixed with reducing sugars such as sucrose or glucose. These reducing sugars act as a source of electrons for the reduction of nitrite to nitric oxide. However, these nitric oxide-releasing nanoparticles or sialin hydrogels have their limitations because there must be moisture present to allow the chemical reaction to take place. Thus, this system is impractical for topical use on many areas of the skin when infection is present.
Onychomycosis is a fungal infection of the finger and toenails that is caused by dermatophytes, yeasts, or nondermatophyte molds. The primary site from which the infection originates is the bed of the nail (matrix) and the plate under the surface of the nail. The infection damages the nail plate resulting in thickening and discoloration and upon progression, in advanced cases, the nail plate lifts away from the nail bed (onycholysis). This often causes discomfort and is painful.
Accordingly, improvements in the treatment of infections, e.g., by S. aureus, toenail fungus, or other infectious organisms, of skin and other soft tissue are still needed.